Butterfly valve assembly

ABSTRACT

A valve assembly has a valve body, a lower bushing, a valve seat, a lower stem, a disc, and an upper stem. The valve body defines a bi-directional flow path therethrough; wherein the valve body has an inner surface, two flange faces, and further defines an upper orifice and a hemispherical lower orifice along an axis perpendicular to the flow path. The lower bushing is housed in the lower orifice, and the lower bushing is configured to tilt within the lower orifice away from the axis. The lower bushing defines a bushing cavity. The valve seat has an outer surface configured to encapsulate the inner surface and the two flange faces of the valve body. The lower stem is housed in the bushing cavity, and the lower stem is configured for tilting away from and towards the axis perpendicular to the flow path. The disc has a seating surface on at outer circumference, defines a stem receptacle to house the lower stem, and the stem receptacle extends less than a diameter of the disc.

STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable.

REFERENCE TO A “SEQUENCE LISTING”, A TABLE, OR A COMPUTER PROGRAM

Not Applicable.

BACKGROUND

Conventional disc and stem butterfly valve throttling assemblies aretypically one-piece disc stem models, two-piece through-stem models, orthree-piece disc and upper/lower stem models, all which possess certaindisadvantages. To note, one-piece disc stem butterfly valve assembliesare limited to construction with one type of material which may not beideal for all the different parts and functions of the device, and aredifficult and expensive to manufacture and repair. These conventionalone-piece models are not preferred in many industries, such as thetrucking or vehicular industry. Two-piece models, while allowing for thestem and disc to be constructed of different materials, are oftencumbersome to assemble, lower flow volume, and, like the one-piecemodels, also suffer from complicated and expensive repairs. Theconventional three-piece design has all the advantages of the one-pieceand two-piece models, but is still expensive to manufacture and repairor difficult to disassemble for repair depending upon the particulardesign. Some of these conventional designs may also require externalopenings on the valve body to aid in lower stem installation orretention, which results in an additional source for corrosion, entrypoints for contaminates, and increased difficulties for repair.

Thus, there is a need for functional multiple-piece disc and stemembodiments which allow the use of dissimilar materials for stem anddisc components; enable the stem component to be made of a strongerand/or more economical material than the disc component; arerebuildable; and, also allow for easy disassembly for replacement ofwear components.

BRIEF SUMMARY OF THE EMBODIMENTS

A solid body resilient seated butterfly valve that has a thin disc, nohardware in the flow path; is readily rebuildable and is sealed from theenvironment; and achieved by means of a disc that is tiltable (and insome embodiments pivotable) into place. The valve assembly has a valvebody, a lower bushing, a valve seat, a lower stem, a disc, and an upperstem. The valve body defines a bi-directional flow path therethrough;wherein the valve body has an inner surface, two flange faces, andfurther defines an upper orifice and a hemispherical lower orifice alongan axis perpendicular to the flow path. The lower bushing is housed inthe lower orifice, and the lower bushing is configured to tilt withinthe lower orifice away from the axis. The lower bushing defines abushing cavity. The valve seat has an outer surface configured toencapsulate the inner surface and the two flange faces of the valvebody. The lower stem is housed in the bushing cavity, and the lower stemis configured for tilting away from and towards the axis perpendicularto the flow path. The disc has a seating surface on at outercircumference, defines a stem receptacle to house the lower stem, andthe stem receptacle extends less than a diameter of the disc.

While the embodiments herein describe parts and/or features of thebutterfly valve assemblies with the terms “upper” and “lower” withrespect to a notch or top plate, it is to be appreciated that theembodiments are not limited to one orientation and may be rotated,oriented or flipped at any angle. By way of example only, but notlimited to, the notch or top plate may be oriented towards the ground,and a lower stem and a lower bushing may be physically upwards.Likewise, the notch or top plate may be oriented laterally. Thenomenclature as written and shown herein remains unchanged in theforegoing examples. Therefore, the terms “upper” and “lower” as usedherein are intended to cover all other orientations even when the partsand/or features are not truly in practice “upper” and/or “lower”.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The embodiments may be better understood, and numerous objects,features, and advantages made apparent to those skilled in the art byreferencing the accompanying drawings. These drawings are used toillustrate only typical embodiments of this invention, and are not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments. The figures are not necessarily to scaleand certain features and certain views of the figures may be shownexaggerated in scale or in schematic in the interest of clarity andconciseness.

FIG. 1 depicts a perspective exploded view of an embodiment of abutterfly valve assembly.

FIG. 2 depicts a perspective partially exploded view of an embodiment ofa butterfly valve assembly.

FIG. 3A depicts top perspective assembled view of an embodiment of abutterfly valve assembly in an open position.

FIG. 3B depicts a side assembled view (partially showing hidden lines)of an embodiment of a butterfly valve assembly in an open position.

FIG. 3C depicts a cross sectional assembled view of an embodiment of abutterfly valve assembly in an open position along line 3C-3C of FIG.3B.

FIG. 3D depicts a front assembled view of an embodiment of a butterflyvalve assembly in an open position.

FIG. 4A depicts a perspective view of one embodiment of a ball shapedlower bushing.

FIG. 4B depicts a top view of one embodiment of a ball shaped lowerbushing.

FIG. 4C depicts a cross section view of an embodiment of a ball shapedlower bushing along line 4C-4C of FIG. 4B.

FIG. 5A depicts a perspective exploded view of a “spring stem”alternative embodiment of a butterfly valve assembly.

FIG. 5B depicts a side assembled view (partially showing hidden lines)of a “spring stem” alternative embodiment of a butterfly valve assembly.

FIG. 5C depicts a cross sectional assembled view of a “spring stem”embodiment of a butterfly valve assembly in an open position along line5C-5C of FIG. 5B.

FIG. 5D depicts a front assembled view of a “spring stem” alternativeembodiment of a butterfly valve assembly.

FIG. 5E depicts a perspective assembled view of a “spring stem”alternative embodiment of a butterfly valve assembly.

FIG. 6A depicts a perspective exploded view of a “ball end stem”alternative embodiment of a butterfly valve assembly.

FIG. 6B depicts a side assembled view (partially showing hidden lines)of a “ball end stem” alternative embodiment of a butterfly valveassembly.

FIG. 6C depicts a cross sectional assembled view of a “ball end stem”embodiment of a butterfly valve assembly in an open position along line6C-6C of FIG. 6B.

FIG. 6D depicts a front assembled view of a “ball end stem” alternativeembodiment of a butterfly valve assembly.

FIG. 6E depicts a perspective assembled view of a “ball end stem”alternative embodiment of a butterfly valve assembly.

FIG. 7A depicts a side view of one embodiment of a ball end stem.

FIG. 7B depicts a cross section view of an embodiment of a ball end stemalong line 7B-7B of FIG. 7A.

FIG. 7C depicts a top view of an embodiment of a ball end stem.

FIG. 8A depicts a perspective exploded view of a “flat bushing”alternative embodiment of a butterfly valve assembly.

FIG. 8B depicts a side assembled view (partially showing hidden lines)of a “flat bushing” alternative embodiment of a butterfly valveassembly.

FIG. 8C depicts a cross sectional assembled view of a “flat bushing”embodiment of a butterfly valve assembly in an open position along line8C-8C of FIG. 8B.

FIG. 8D depicts a front assembled view of a “flat bushing” alternativeembodiment of a butterfly valve assembly.

FIG. 8E depicts a perspective assembled view of a “flat bushing”alternative embodiment of a butterfly valve assembly.

FIG. 9A depicts a perspective view of one embodiment of a flat bushing.

FIG. 9B depicts a side view of one embodiment of a flat bushing.

FIG. 9C depicts a front view of one embodiment of a flat bushing.

FIG. 9D depicts a top view of one embodiment of a flat bushing.

FIG. 10A depicts a perspective exploded view of a unitary disc and lowerstem piece alternative embodiment of a butterfly valve assembly.

FIG. 10B depicts a side assembled view (partially showing hidden lines)of a unitary disc and lower stem piece alternative embodiment of abutterfly valve assembly.

FIG. 10C depicts a cross sectional assembled view of a unitary disc andlower stem piece embodiment of a butterfly valve assembly in an openposition along line 10C-10C of FIG. 10B.

FIG. 10D depicts a front assembled view of a unitary disc and lower stempiece alternative embodiment of a butterfly valve assembly.

FIG. 10E depicts a perspective assembled view of a unitary disc andlower stem piece alternative embodiment of a butterfly valve assembly.

FIG. 11 depicts a perspective view of one embodiment of a unitary discand lower stem piece.

FIG. 12 depicts a perspective partially exploded view of an embodimentof a butterfly valve assembly similar to FIG. 2 but showing a breakawayportion of the valve body in the region of insertion of the ball shapedlower bushing and lower stem.

FIG. 13 depicts a perspective view of another embodiment of a bushing asa cylindrical shaped lower bushing.

FIG. 14 depicts a perspective view of another embodiment of a bushing asan elliptical-body shaped lower bushing.

DETAILED DESCRIPTION OF EMBODIMENT(S)

The description that follows includes exemplary apparatus, methods,techniques, and instruction sequences that embody techniques of theinventive subject matter. However, it is understood that the describedembodiments may be practiced without these specific details.

One embodiment of the butterfly valve assembly 100 is depicted in FIGS.1, 2, 3A-D, and 12. In butterfly valve assembly 100, a flow-path orbi-directional flow path 190 flows through a one-piece valve body 110which has a valve body inner surface 114 and two flange faces 119 a and119 b located on opposite sides of the valve body 110 adjacent the valvebody inner surface 114. The one-piece valve body 110 has no counterboresand preferably defines an inner diameter of constant length. Theone-piece valve body 110 further defines valve body upper and lowerorifices 112 a and 112 b arranged respectively at the top and bottom ofthe valve body inner surface 114, each orifice 112 diametrically acrossfrom the other. Valve body lower orifice 112 b may be machined or formedinto the valve body 110, and does not open to the valve body outersurface 116 in the preferred embodiments (i.e. the valve body lowerorifice 112 b is formed on the internal or valve body inner surface 114and terminates in depth prior to emerging at the external or valve bodyouter surface 116). Valve body upper orifice 112 a is also machined intothe valve body 110 and runs through a neck 118 and notch plate 170. Theneck 118 is connected to the notch plate 170, which defines a notchplate aperture 172. Valve body upper orifice 112 a and notch plateaperture 172 are of a diameter sufficient to allow upper bushing 180 andan upper stem 120 to pass there through. The neck 118 and notch plate170, as depicted in a preferred embodiment although not limited to inother embodiments, are unitary with the valve body 110. Although thenotch plate 170 is depicted with a span of ninety (90) degrees of notchplate 170 teeth or notch plate 170 notches, the notch plate 170 may haveany span of degrees of such teeth or notches as necessary, including butnot limited to one hundred and eighty (180) degrees. Valve body 110 mayalso be manufactured with alignment ears 115 and valve body notches 117for the purpose of alignment within the flow system.

The one-piece valve seat 160 is made of any suitable flexible materialknown to one having ordinary skill in the art. The valve seat 160 isone-piece, has no counterbores, preferably defines an inner diameter ofconstant length, and has a valve seat outer surface 166 which forms afluid-tight seal with (i.e. encapsulates) the valve body inner surface114 when assembled. Furthermore, valve seat 160 may also wrap aroundvalve body inner surface 114 to fully or partially encapsulate theflange faces 119 a and 119 b of the valve body 110, acting as a sealinggasket against the mating flange (not shown). This particular model ofvalve seat 160 is commonly referred to in the industry as a ‘boot seat’design. Valve seat 160 also defines valve seat upper and lower stemopenings 162 a and 162 b, the centers of which correspond respectivelyto the centers of valve body upper and lower orifices 112 a and 112 b toallow upper stem 120 and lower stem 130 to pass therethrough. An axis102 defines the longitudinal axis for which the centers of valve seatopenings 162, valve body orifices 112, and notch plate aperture 172align along.

As illustrated in the embodiment of FIGS. 1, 2, 3A-D, and 12 the valvebody lower orifice 112 b is configured to house a ball shaped (exteriorsurface) lower bushing 140 (e.g. defines a hemispherical void within theone-piece valve body 110). A perspective view of ball shaped lowerbushing 140 is depicted in FIGS. 4A-C. The ball shaped lower bushing 140may be constructed out of any suitable material as known to one ofordinary skill in the art including, but not limited to, stainless steelor acetyl. In addition, ball shaped lower bushing 140 defines a bushingcavity 142, which is configured to house a portion of lower valve stem130. The valve body lower orifice 112 b is constructed or formed as ahemispherical void or cavity such that the ball shaped lower bushing 140can tilt and rotatably maneuver or pivot within the valve body lowerorifice 112 b. While ball shaped lower bushing 140 is depicted in theform of a sphere and the valve body lower orifice 112 b is defined as ahemispherical void (or cylindrical void with hemispherical void at thelower end), it is to be appreciated that the combination of lowerbushing 140 and valve body orifice 112 b may be in any combination offorms, shapes, or voids capable of swiveling, tilting, or pivoting thelower bushing 140. When the lower stem 130 is inserted into the bushingcavity 142, the rotation or pivoting movement of the ball shaped lowerbushing 140 is imparted to the lower stem 130. The interaction betweenthe valve body lower orifice 112 b and the ball shaped lower bushing 140allows the lower stem 130 to pivot and tilt axially away from axis 102at a variety of different angles, one of which may be seen in FIG. 2.The ends of lower stem 130 may be beveled if so desired (not shown).

The circumference or diameter of valve seat opening for lower stem 162 bmay be less than the widest circumference or diameter of the ball shapedlower bushing 140. As a result, when valve seat 160 is fitted againstthe valve body 110, the ball shaped lower bushing 140 is retained in thevalve body lower orifice 112 b. Further the circumference or diameter ofthe valve seat lower stem opening 163 b may combine into an interferencefit, forming a fluid-tight or leak-proof seal with the lower stem outersurface 134. The circumference of the valve seat upper stem opening 163a may also combine into an interference fit forming a fluid-tight orleak-proof seal with the upper stem outer surface 124.

Disc 150 is of a flat, circular shape, of primarily uniform thicknessexcept for upper and lower stem retaining sections 156 a and 156 b. Thethickness of the disc 150 around the stem retaining sections 156 isincreased so as to be able to accommodate the housing of upper stem 120and lower stem 130 in upper and lower stem receptacles 152 a and 152 b,respectively. Upper and lower stem receptacles 152 a and 152 b arecentered on and concentric with the centerline (pivot axis from edgethrough center of disc that aligns with axis 102 when the disc 150 isinstalled) of disc 150. Note that it is not necessary for upper andlower stem receptacles 152 to form a through shaft hole through the disc150. Each of the upper and lower stem receptacles 152 may extend intothe disc only as is deemed necessary by one skilled in the art (by wayof example only, but not limited to, within a range of about 1.0 to 2.5times the diameter of the opening, and in some cases about 1.5 times thediameter). No fasteners are required for the upper and lower stemreceptacles 152. This allows the disc to have a slim disc profile(relative to upper stem receptacle 152 a and lower stem receptacle 152b) which enhances flow, with much higher CVs. The drive connectionbetween the upper stem 120 and the upper stem receptacle 152 a could beany known drive connection such as, for example, a double “D”-typeconnection, a hex-drive, a splined drive, or a keyed-drive. In addition,although disc 150 is illustrated with a flat, circular shape, it is tobe appreciated that any shape of the disc 150 may be used in connectionwith the disclosed embodiments. The seating surface 158 of the disc 150is located at or around the external perimeter of the disc 150.

To assemble butterfly valve assembly 100, the ball shaped lower bushing140 is first inserted into the valve body lower orifice 112 b. The valveseat 160 is then fitted into the valve body 110 such that the center ofthe valve seat opening for the upper stem 162 a and the center of valveseat opening for the lower stem 162 b are aligned with axis 102. Thevalve seat 160 can be installed in the valve body 110 from either theupstream side or the downstream side of the valve body 110. When thevalve seat 160 is installed properly, the valve seat outer surface 166forms a fluid-tight seal against, i.e. encapsulates the inner diameteror valve body inner surface 114 and the flange faces 119 a and 119 b ofthe valve body 110.

Then, one end of the lower stem 130 is inserted (or pushed because thevalve seat 160 seals against the lower stem 130) through the valve seatopening for lower stem 162 b into the bushing cavity 142. From there,the lower stem 130 can be tilted and/or pivoted away from axis 102 (byforce as the flexible valve seat 160 offers some resistance) and theopposite end of lower stem 130 can be inserted into lower stemreceptacle 152 b of disc 150. In an alternate way to install the lowerstem 130 and disc 150, one end of lower stem 130 can be first insertedinto the lower stem receptacle 152 b of disc 150. Then, the opposite endof lower stem 130 is axially, pivotably, or tiltably inserted into thevalve seat opening for the lower stem 162 b and into the bushing cavity142.

The disc 150 can then be axially tilted towards axis 102 such that thecenter of the bore of upper stem receptacle 152 a aligns with thecenters of valve body upper orifice 112 a and valve seat opening forupper stem 162 a and the axis 102 (the ball shaped lower bushing 140,lower stem 130 and disc 150 can all be tilted greater than 0° and lessthan 90° away from the axis 102 in any direction away from the axis102). The upper stem 120 is then inserted through an upper bushing 180,notch plate aperture 172, neck 118, valve body upper orifice 112 a andvalve seat opening for upper stem 162 a into the upper stem receptacle152 a of disc 150. Note that the upper stem 120 may feature any numberof surfaces, splines, torque transmitting or flat surfaces 128 and maybe in any shape. As shown in the FIG. 1 embodiment, but not limited to,the flat surfaces 128 matingly correspond to the shape of upper stemreceptacle 152 a within disc 150 to form a drive connection such thatwhen the upper stem 120 is actuated or rotated, the motion istransferred to the disc 150, and thus the disc 150 correspondinglyrotates. The disc 150 seals in both directions (downstream and upstream)along the seating surface 158 against the valve seat 160 as the valveseat 160 is of constant inner diameter. Rotation of the upper stem 120may be accomplished by an actuator (not depicted), of any type bestdetermined by one of ordinary skill in the art, including, but notlimited to: a manual, electric, or pneumatic type actuator. A notchplate 170 may be used in connection with an actuator so that thebutterfly valve assembly 100 may be set into an open, closed, orpartially open position, as is known in the art. Further, additionalbushings 182 or washers, retainers, O-rings, or packing rings 126 may bemounted around upper stem 120. As examples, washers, retainers, O-rings,or packing rings 126 may be made of steel or acetyl, but are not limitedto as such.

The use of the pivotable and/or axially tiltable lower stem 130 enablesthe use of a one-piece, unitary valve body 110, which is stronger, moreeconomical to manufacture, and preferred in many industries. The axiallytiltable lower stem 130 eliminates any external openings that resultfrom the use of plugs through which the stem is inserted or roll pins toretain the stems. As a result, use of a one-piece valve body 110 withoutan external side opening for insertion of lower stem 130 also lowers thepotential for corrosion and eliminates entry points for contaminates.

An open position of the butterfly valve assembly 100 is depicted inFIGS. 3A-D, where the disc outer circumference 154 does not lie flushagainst the valve seat inner surface 164, and fluid may move through theflow path 190. When disc 150 is rotated via the upper stem 120 such thatthe disc outer circumference 154 lies sealed in a fluid-tight manneragainst the valve seat inner surface 164 (not shown), then the butterflyvalve assembly 100 is in the fully closed position, and the flow path190 is fully obstructed by disc 150.

FIGS. 5A-E depict a “spring stem” type butterfly valve assembly 200. Inthe butterfly valve assembly 200, the ball shaped lower bushing 140 isreplaced with a spring stem lower bushing 240. Instead of a sphericalshape, spring stem lower bushing 240 has a hollow tubular shape, theinside surface of which defines a spring stem bushing cavity 242. Thevalve body lower orifice 212 b is formed in the shape of acylindrical-shaped void to matingly house the spring stem lower bushing240. Valve body lower orifice 212 b is machined into the valve body 110,and does not open to the valve body outer surface 116. Valve body lowerorifice 212 b is constructed such that rotational movement of the upperstem 120 and hence the disc 150 about the axis 102 is not inhibited byspring stem lower bushing 240, spring 244, or lower stem 130.

The valve seat 160 is fitted against the valve body 110 such that thevalve seat outer surface 166 forms a fluid-tight seal against the valvebody inner surface 114 and the flange faces 119 a and 119 b. The spring244 is then placed within or encapsulated by the spring stem bushingcavity 242 of spring stem lower bushing 240. As depicted, the spring 244is a compression coil spring, but spring 244 may be any type ofcompressible spring or material best known to one of ordinary skill inthe art. The lower stem 130 is then placed on top of the spring 244,which is subsequently compressed downwards (hence the lower stem 130 isspring-loaded). The disc 150 is inserted into the valve seat 160 in anorientation which aligns the centers of the upper stem receptacle 152 a,the valve seat opening for upper stem 162 a, and the lower stemreceptacle 152 b with the axis 102. When the centers of the valve bodylower orifice 212 b, valve seat opening for lower stem 162 b and lowerstem receptacle 152 b are aligned with axis 102, the spring 244decompresses and expands, thus pushing the uppermost portion of thelower stem 130 into the lower stem receptacle 152 b. In an alternate wayto install lower stem 130 and disc 150, the lower stem 130 may be tiltedor pivoted away from axis 102 (by force as the flexible valve seat 160offers some resistance), and the opposite end of lower stem 130 can beinserted into lower stem receptacle 152 b of disc 150. Then, the lowerstem 130 and disc 150 may be pivoted into the appropriate position intovalve seat 160, wherein the centers of the upper stem receptacle 152 a,the valve seat opening for upper stem 162 a, and the lower stemreceptacle 152 b are aligned with the axis 102. After installation ofthe lower stem 130 and disc 150, the upper stem 120 may then be insertedinto the upper stem receptacle 152 a of disc 150 and may be rotated oractuated in a similar manner to the butterfly valve assembly 100embodiment as described for FIGS. 1, 2, 3A-D, and 12.

FIGS. 6A-E depict a “ball end stem” type of butterfly valve assembly300. In this butterfly valve assembly 300, the ball shaped lower bushing140 and lower stem 130 from butterfly valve assembly 100 are replacedwith an integral, single-piece ball end stem 340. FIGS. 7A-C depict aside view of the ball end stem 340. Ball end stem 340 is constructedwith a ball end 342 of ball end stem 340, and stem portion 330 of ballend stem 340. The ball end 342 of the ball end stem 340 is inserted intovalve body lower orifice 112 b. Valve body lower orifice 112 b ismachined as a rounded bottom hemispherical void into the valve body 110to allow rotatable movement of the ball end stem 340. Valve seat 160 ismounted into valve body 110 such that the valve seat opening for theupper stem 162 a is aligned with the valve body upper orifice 112 a. Thevalve seat opening for the lower stem 162 b is mounted over the stemportion 330 of ball end stem 340 such that the stem portion 330 of ballend stem 340 protrudes therethrough. Further, the circumference of thevalve seat lower stem opening 163 b may form a fluid-tight seal with thestem portion outer surface 334. The stem portion 330 of ball end stem340 is capable of rotation and pivotal movement and tilting axially awayand towards the axis 102, such that stem portion 330 of ball end stem340 can be inserted axially into the lower stem receptacle 152 b of thedisc 150. Assembly of the upper stem 120 into upper stem receptacle 152a of disc 150 is the same as was described for the butterfly valveassembly 100 embodiment.

FIGS. 8A-E depict another embodiment as a “flat bushing” type butterflyvalve assembly 400. In the butterfly valve assembly 400, a bushing 440is configured with rounded sides 446, flats 444, and a flat bushingcavity 442. FIGS. 9A-D depict a side view of the bushing 440. Valve body110 defines a journal 412 b to house bushing 440. Journal 412 b is avoid machined into the valve body 110, configured with journal roundedsurfaces 416 which mate with bushing rounded sides 446, thus enablingaxial tilt towards and away from axis 102, along the flow path 190.Further, journal 412 b is also configured with journal flat surfaces 414which mate with bushing flats 444, thus prohibiting rotation around axis102. The “flat bushing” type butterfly valve assembly 400 could bereplaced by other embodiments of bushings such as a cylinder tiltingalong its rounded side or a bushing having an elliptical profile.

To assemble, the bushing 440 is deposited into the journal 412 b suchthat the bushing rounded sides 446 are adjacent to journal roundedsurfaces 416 and the bushing flats 444 are adjacent to journal flatsurfaces 414. The valve seat 160 is then inserted into the valve body110 such that the centers of valve seat opening for the upper stem 162a, the valve body upper orifice 112 a, the valve seat opening for thelower stem 162 b, and journal 412 b are aligned with axis 102.

Then, one end of the lower stem 130 is inserted or pushed through valveseat opening for lower stem 162 b into the bushing cavity 442. Fromthere, the lower stem 130 can be tilted away or pivoted away from axis102 (by force as the flexible valve seat 160 offers some resistance),and the opposite end of lower stem 130 can be inserted into lower stemreceptacle 152 b of disc 150. In an alternate way to install the lowerstem 130 and disc 150, one end of lower stem 130 can be first insertedinto the lower stem receptacle 152 b of disc 150. Then, the opposite endof lower stem 130 is axially, pivotably, or tiltably inserted into thevalve seat opening for the lower stem 162 b and into the bushing cavity442 (the bushing 440, lower stem 130 and disc 150 can all be tiltedgreater than 0° and less than 90° away from the axis 102 in only twoopposite directions, such two directions being aligned with the axis ofthe flow path). Pivoting the disc 150 such that the upper stem 120 canbe inserted into upper stem receptacle 152 a of disc 150 of thebutterfly valve assembly 400 follows in a similar manner to butterflyvalve assembly 100 as described for FIGS. 1, 2, 3A-D, and 12.

FIGS. 10A-E depict a unitary disc and lower stem piece embodiment 500 ofthe butterfly valve assembly. In this unitary disc and lower stem pieceembodiment 500, the lower stem 130 and disc 150 of butterfly valveassembly 100 are replaced with an integral, single-piece stem and disc550 unified or joined at lower stem retaining boss 556 b. Integral stemand disc 550 features an Integral disc 558 portion and an Integral stem530 portion, as depicted in FIG. 11. Integral disc 558 has an outercircumference of 554, configured to sit with a fluid-tight seal againstvalve seat inner surface 164 when assembled and set into the closedposition.

In the unitary disc and lower stem piece embodiment 500, the bushing 40or ball shaped lower bushing 140 and valve seat 160 are installed muchin a similar manner as is depicted in the butterfly valve assembly 100of FIGS. 1, 2, 3A-D, and 12. Bushing 40 represented here as a ballshaped lower bushing 140 retains the same rotational and pivotalcapability as in the butterfly valve assembly 100. After theinstallation of the ball shaped lower bushing 140 and valve seat 160into valve body 110, the Integral stem 530 is inserted at an angletilted or pivoted away from the axis 102 into the bushing cavity 142 ofball shaped lower bearing 140. The circumference of the valve seat lowerstem opening 163 b may form a fluid-tight seal with the Integral stemouter surface 534. Then, the ball shaped lower bushing 140 and Integraldisc and stem 550 can be tilted towards the axis 102 such that center ofthe upper stem receptacle 552 a and upper stem retaining section 556 aaligns with the axis 102. In this position, the upper stem 120 is ableto pass through the upper bushing 180, a notch plate aperture 172 in thenotch plate 170, through the neck 118, the valve body upper orifice 112a and valve seat opening for upper stem 162 a into the stem receptacle552 a of Integral stem and disc 550.

Other types or designs of bushings may be implemented. By way ofexample, FIG. 13 depicts a perspective view of another embodiment of abushing 40 as a cylindrical shaped lower bushing 640. By way of example,FIG. 14 depicts a perspective view of another embodiment of a bushing 40as an elliptical-body shaped lower bushing 740. In the foregoingexamples, the valve body lower orifice 112 b may be modified to housethe respective embodiment of bushing 40 to be implemented such that thebushing 40 is capable of swiveling, tilting, or pivoting movement. Inuse of the term “tilt” or “tilting” the axis of the disc 150, lower stem130 and/or bushing 40 is tipped or inclined away (see, for example, FIG.2 and FIG. 12) from its regular axis 102 of rotation/operation asfurther described above.

While the embodiments are described with reference to variousimplementations and exploitations, it will be understood that theseembodiments are illustrative and that the scope of the inventive subjectmatter is not limited to them. Many variations, modifications, additionsand improvements are possible. For example, the techniques used hereinmay be applied to any valve used for piping systems.

Plural instances may be provided for components, operations orstructures described herein as a single instance. In general, structuresand functionality presented as separate components in the exemplaryconfigurations may be implemented as a combined structure or component.Similarly, structures and functionality presented as a single componentmay be implemented as separate components. These and other variations,modifications, additions, and improvements may fall within the scope ofthe inventive subject matter.

The invention claimed is:
 1. A valve assembly, comprising: a valve bodydefining a flow path therathough; wherein the valve body has an innersurface and further defines an upper orifice and a lower orifice alongan axis perpendicular to the flow path; a lower bushing housed in thelower orifice wherein the lower bushing defines a bushing cavity; avalve seat, wherein an outer surface of the valve seat is configured toencapsulate the inner surface of the valve body; a lower stem housed inthe bushing cavity, wherein the bushing is configured for tilting,wherein the lower stem is configured for tilting, and wherein the lowerstem is configured for inserting at an opposite end into a disc; and thedisc having a seating surface on an outer circumference, wherein thedisc is mounted via the lower stem into the valve body.
 2. The valveassembly according to claim 1, wherein the lower orifice terminates at adepth prior to emerging at a valve body outer surface.
 3. The valveassembly according to claim 2, wherein the flow path is a bi-directionalflow path.
 4. The valve assembly according to claim 3, wherein the valvebody is a one-piece valve body.
 5. The valve assembly according to claim1, wherein the lower bushing is configured to tilt within the lowerorifice away from the axis; and further wherein the lower stem isconfigured for tilting away from and towards the axis.
 6. The valveassembly according to claim 5, wherein the disc defines a stemreceptacle to house the lower stem, and wherein the stem receptacleextends less than a diameter of the disc.
 7. A valve assembly having avalve body with an inner surface defining a flow path therethrough,wherein the valve assembly further has an axis perpendicular to the flowpath, comprising: an upper orifice defined on an upper side of the innersurface, wherein the upper orifice is aligned along the axis; a lowerorifice defined on a lower side of the inner surface, wherein the lowerorifice is aligned along the axis; a lower bushing housed in the lowerorifice, wherein the lower bushing defines a bushing cavity; a lowerstem inserted at one end into the lower bushing, wherein the bushing isconfigured for tilting, wherein the lower stem is configured fortilting, and wherein the lower stem is configured for inserting at anopposite end into a disc; a valve seat having an outer surfaceencapsulating the inner surface of the valve body, wherein the valveseat defines an upper opening aligned with the upper orifice and a loweropening aligned with the lower orifice; an upper receptacle defined inan upper end of the disc, wherein the upper receptacle is configured toalign with the upper orifice; and a lower receptacle defined in a lowerend of the disc, wherein the lower receptacle is configured to alignwith the lower orifice and house the opposite end of the lower stem. 8.The valve assembly of claim 7, wherein an outer circumference of thedisc sealingy engages the valve seat.
 9. The valve assembly of claim 7,wherein the lower orifice is a hemispherical void and further whereinthe lower bushing has a spherical exterior surface.
 10. The valveassembly of claim 7, wherein the lower stem is inserted at the one endinto the bushing cavity.
 11. The valve assembly of claim 7, wherein thelower orifice is a cylindrical void; wherein the lower bushing has atubular shape, and wherein the valve assembly further comprises a springhoused in the lower bushing below the lower stem.